Nowadays, in view of protecting global environment, there is a need of a power source with a high output power and a high capacity to apply to a low-emission vehicle such as electronic vehicle or hybrid vehicle. In a field outside of vehicles, since mobile devices such as information related devices and communication devises are now widely used on a global basis, there is also a need of a power source that can make such mobile devices high-performance.
In a case that a battery such as a lithium battery is used as a power source, especially when the battery is used as a large power source for equipping in a vehicle such as an electronic vehicle or a hybrid vehicle, it is preferable to laminate a plurality of unit cells to make a laminated battery, and further preferable to connect a plurality of laminated batteries to make an assembled battery. In particular, by connecting the plurality of laminated batteries in series, it is possible to obtain a high-powered assembled battery, which is suitable to use as a large power source for equipping in a vehicle.
For example, in Patent Document 1, in an outer periphery of a plurality of unit cells that are laminated, the plurality of unit cells are further laminated to make a battery bundle (laminated battery), then a plurality of battery bundles are connected in series to configure an assembled battery. According to Patent Document 1, it is possible to form a battery bundle easily and in a cost-effective way.